e. Aside from the personal interest that attaches to the
picturesque career, so typically American, there is a broader aspect in
which the work of the "Franklin of the Nineteenth Century" touches
the welfare and progress of the race. It is difficult at any time to
determine the effect of any single invention, and the investigation
becomes more difficult where inventions of the first class have been
crowded upon each other in rapid and bewildering succession. But it will
be admitted that in Edison one deals with a central figure of the great
age that saw the invention and introduction in practical form of the
telegraph, the submarine cable, the telephone, the electric light, the
electric railway, the electric trolley-car, the storage battery, the
electric motor, the phonograph, the wireless telegraph; and that the
influence of these on the world's affairs has not been excelled at
any time by that of any other corresponding advances in the arts and
sciences. These pages deal with Edison's share in the great work of the
last half century in abridging distance, communicating intelligence,
lessening toil, improving illumination, recording forever the human
voice; and on behalf of inventive genius it may be urged that its
beneficent results and gifts to mankind compare with any to be credited
to statesman, warrior, or creative writer of the same period.

Viewed from the standpoint of inventive progress, the first half of
the nineteenth century had passed very profitably when Edison
appeared--every year marked by some notable achievement in the arts and
sciences, with promise of its early and abundant fruition in commerce
and industry. There had been exactly four decades of steam navigation
on American waters. Railways were growing at the rate of nearly
one thousand miles annually. Gas had become familiar as a means of
illumination in large cities. Looms and tools and printing-presses were
everywhere being liberated from the slow toil of man-power. The first
photographs had been taken. Chloroform, nitrous oxide gas, and ether
had been placed at the service of the physician in saving life, and
the revolver, guncotton, and nitroglycerine added to the agencies for
slaughter. New metals, chemicals, and elements had become available in
large numbers, gases had been liquefied and solidified, and the range
of useful heat and cold indefinitely extended. The safety-lamp had been
given to the miner, the caisson to the bridge-builder, the